The present invention relates to automatic transmissions and, more particularly, to an improved overdrive piston retainer for Chrysler 42RE, 42RH, 46RE, 46RH, 47 RE, and 47 RH automotive transmissions (hereinafter xe2x80x9cChrysler transmissionsxe2x80x9d).
The overdrive piston retainer in the aforementioned Chrysler transmissions functions as a receptacle for the overdrive piston and interconnects the reverse drum component disposed within the transmission housing to the overdrive assembly, which is mounted on the exterior of the housing. The intermediate shaft of the transmission extends coaxially through the reverse drum, through the hub diameter of the piston retainer, exits through the transmission housing, and engages the overdrive clutch assembly, which is mounted onto the aft side of the housing.
The original equipment manufacture (hereinafter xe2x80x9cOEMxe2x80x9d) piston retainer in the Chrysler transmissions is susceptible to premature wear and galling on the hub diameter, which rotationally engages and supports the mating reverse drum. This is due in part to the clearance (0.015-0.020 inches), which must be maintained between these components to allow for thermal expansion of the hub diameter during operation. Galling between the mating surfaces of the OEM piston retainer hub diameter and reverse drum typically occurs adjacent a lubrication site (i.e. a circular machined flat and oil hole) that is located at a 12 o""clock (i.e. with reference to a superimposed clock face) or zero degree position at top dead-centre on the vertical centerline of the hub diameter.
Thus, the present invention has been developed to solve this problem providing a replacement overdrive piston retainer for the OEM overdrive piston retainer, which is standard equipment on the Chrysler transmissions and will be referred to throughout this specification.
Accordingly, the present invention provides a replacement overdrive piston retainer wherein a plurality of lubrication sites are positioned at predetermined locations to deliver lubricant evenly about the hub diameter and, more particularly, to the rotational contact interface between the hub diameter and the mating reverse drum that is susceptible to galling. In addition, lubrication reservoirs have been machined on the inside diameter (hereinafter xe2x80x9cI.D.xe2x80x9d) of the hub diameter in fluid communication with the lubrication sites and with the cooler lube circuit to improve the flow of lubrication through the piston retainer to the mating surfaces of the hub diameter and reverse drum. Further, an annular groove with an O-ring seal has also been added to a shoulder diameter adjacent the hub diameter to retain automatic transmission fluid (hereinafter xe2x80x9cATFxe2x80x9d) between the hub diameter interface and the transmission housing.
There has thus been outlined, rather broadly, the important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.